This browser is no longer supported.
Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support.
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(83.2, 25%, 18%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3ECC%3C/text%3E%3C/svg%3E)
By using Exchange Online Receiver Connector as the SMTPmail relay to On-prem Mailbox in Exchange Hybrid mode, will the mail store somewhere during its routes through the Online Connector?
Customer would like to use the EOP function but is concerned abt the data storage (they are not allowed to have any mail data on-cloud). Can anyone share any official document explaining where the data will be stored please?
Mail is not stored anywhere in a connector unless there is an issue connecting to your on-prem server.
In that scenario, the mail will queue in Exchange Online for up to one day.
This is true across the board, if a customer sends you mail and your server cant be reached, then mail will queue and it could be in any on-prem or cloud service.
Hi @Andy David - MVP , thank you a lot for your reply. Together with Aholic's answer below, I believe these should be able to address the question. Cheers~
![](data:image/svg+xml, %3Csvg xmlns='http://www.w3.org/2000/svg' height='64' class='font-weight-bold' style='font: 600 30.11764705882353px "SegoeUI", Arial' width='64'%3E%3Ccircle fill='hsl(41.6, 80%, 14%)' cx='32' cy='32' r='32' /%3E%3Ctext x='50%25' y='55%25' dominant-baseline='middle' text-anchor='middle' fill='%23FFF' %3EAL%3C/text%3E%3C/svg%3E)
Hi @ Corrine Chen ,
Just wondering if you set up quarantine policies?
After EOP inspects the mails, if malware is found in the message or attachment, the message is delivered to quarantine.
For normal mail, as Andy said, it will be routed to an on-premises mailbox and will not be saved in the cloud.
Please refer to this link for the workflow of EOP ：Exchange Online Protection (EOP) overview - Office 365 | Microsoft Learn
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.
Hi @Aholic Liang-MSFT , thank you very much for your additioinal input. I think it solves my question now. Cheers~
Hi @ Corrine Chen ,
You are welcome. I wish you all the best in your work.